1. Field of the Invention
The invention relates to a device and a method for measuring electrical variables, having at least one external measuring connection, which can be connected to an electronic device to be tested. The invention relates further to a method for measuring electrical variables of an electrical signal of an electronic device to be tested, the signal, which is to be measured, being applied at an external measuring connection of a measuring device.
The invention relates further to a device for generating electrical variables, having at least one external connection, which can be connected to an electronic device to be tested. The invention likewise relates to a method for generating an electrical variable via at least one generating device, whereby the generating device has at least one external connection, which is connected to an electronic device to be tested.
2. Description of the Background Art
A device for measuring electrical variables forms an arrangement which can often also be called a measuring channel in common usage. In this regard, the concept of a measuring channel can be understood to be an arrangement of electronic components, whereby a measuring channel on the input side has a measuring connection, at which an electrical signal to be measured can be applied, and on the output side provides a measured value, e.g., at an output connection or in a retrievable memory or by other measures.
In an equivalent way, the device for generating electrical variables concerns an arrangement which is often also called a generating channel in common usage. Within the meaning of the invention, this can relate to an arrangement of electronic components to which on the input side information, e.g., a value or an electrical signal, is provided and which on the output side has an output connection at which a signal formed from the information can be tapped.
The aforementioned devices or methods can be used to test any type of electrical or electronic devices. In an example use, the device can be used to test control devices for motor vehicles. This special application does not in any way limit the invention described hereafter and serves only as an example for clarifying the function. If use in a motor vehicle control device is mentioned in an example, this example is to be understood generally also for any other type of electronic device.
It is known in the conventional art, for example, to test vehicle control devices in a simulated environment, to thus check the behavior of a vehicle control device simulatively in a later, actual, real-time operation. This type of test is typically called, for example, HIL (“hardware in the loop”).
It is essential for such a test of a vehicle control device that such a vehicle control device is acted upon from the outside by certain electrical variables, for example, by electrical variables that occur in specific real-time operation during driving of a motor vehicle.
This can refer, e.g., to electrical variables which are provided by certain sensors, operable elements, etc. It is typically provided in this case that a vehicle control device provides output variables depending on input variables after processing or also independent of input variables; these output variables are to be detected and evaluated during a test. In summary, it is therefore essential for conducting such a test, that, on the one hand, electrical variables are provided to a vehicle control device at its inputs and that, on the other, electrical variables are detected and evaluated from the outputs of a motor vehicle device, particularly whereby input variables are provided as part of a simulation and output variables are also processed as part of a simulation.
An electrical variable can be understood to be a variable that is represented by a variable value and a variable type. Typical variable types can be, for example, but not exclusively, current, voltage, resistance, etc.
It can also be provided as part of the invention to process general physical variables, also of a nonelectrical type, which, however, is then represented technically by an electrical variable. For example, the variable types—force, torque, weight, length, time, angle, etc.—can be represented within the scope of a test for a vehicle control device by corresponding electrical variable types, for example, in that a sensor that measures such a variable type provides a corresponding output signal, proportional to the variable, in the form of an electrical variable, e.g., as a voltage or resistance or also a flowing current.
A variable value is further a numerical value and a unit of measurement. For example, a current of three amperes represents a physical variable of the variable type, current, with a variable value that results from the numerical value 3 and the unit of measurement ampere. This applies analogously to any other physical, particularly electrical variables.
Because, as is evident, different physical, particularly electrical variables can be generated or measured only by different measures, it is known in the conventional art that a device adapted for this special variable type is used for measuring or generating a specific physical or electrical variable. Several such devices for measuring or generating a specific physical or electrical variable are often realized on a common interface card or plug-in card for a data processing card.
This means that as part of a test for an electrical device, such as, for example, a vehicle control device, a plurality of different devices must be provided to be able to process the plurality of different physical and particularly electrical variables to be measured or also generated, which arise during a test.
For this reason, prior testing setups are extremely complex and in each case adapted individually to a simulating task to be completed. Known testing devices therefore are complex, cost-intensive, and inflexible, because they can be used only for a specific simulation task to be considered. If other aspects are to be considered as part of a simulation, the corresponding testing device must be changed and adapted to the new task, which is also laborious and cost-intensive.
Channels for measuring or generating a particular physical or electrical variable on a card may also remain unused and, moreover, another card with possibly likewise excessive channels must be used for measuring or generating another physical or electrical variable, as a result of which the space requirement and cost of the system increase.
Moreover, it has been regarded as very disadvantageous thus far in the conventional art that higher-order data processing systems as well, particularly in their programs running therein, must have appropriately adapted interfaces, to be able to deal with measured values of physical, particularly electrical variables of different variable types, and also, if necessary, to be able to create different variable types simulatively.